1. Field of the Invention
The present invention relates to a locking apparatus for a webbing retractor that prevents a take-up shaft winding up an occupant-restraining webbing from rotating in an unwinding direction of the webbing to prevent the webbing from being unwound from the retractor upon the deceleration of a vehicle or the like.
2. Description of the Related Art
This kind of locking apparatus are constructions in which a turning wheel and a lock plate rotating together with a take-up shaft are arranged. The turning wheel on this kind of locking apparatus causes a rotational lag in a webbing unwinding direction toward the take-up shaft upon the deceleration of the vehicle or the like. This moves the lock plate across in the direction of the take-up shaft axis, thereby preventing the take-up shaft from rotating in a webbing unwinding direction.
However, in a locking apparatus of this structure the lock plate is arranged spacedly in a direction of the take-up shaft axis to be allowed to be moved freely in a direction across the take-up shaft. Therefore a problem arose in that the looseness of the lock plate in an axial direction of the take-up shaft causes a clattering noise due to vibration occurring in ordinary running condition of the vehicle. Especially, in the webbing retractor applied to a rear seat of the vehicle where the take-up shaft is arranged in a vertical direction, a clattering noise is very pronounced, because the lock plate is arranged floating in the vertical direction corresponding to the main vibratory direction of the vehicle during ordinary running condition of the vehicle.